Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss attributable to common stockholders	$ (107,294)	$ (153,875)	$ (80,026)
Adjustments to reconcile net loss attributable to common stockholders to net cash used in operating activities:
Depreciation and amortization	24,588	21,216	15,297
Amortization of deferred contract costs	48,161	32,279	17,801
Stock-based compensation	96,046	81,293	34,680
Allowance for credit losses	1,662	960	326
Accretion of marketable securities	(7,492)	(896)	0
Non-cash operating lease expense	5,856	6,205	0
Unrealized loss on strategic investments	1,793	2,896	0
Other	1,178	690	0
Changes in operating assets and liabilities:
Accounts receivable	10,313	(32,309)	(27,000)
Prepaid expenses and other assets	(5,831)	(4)	(9,903)
Deferred contract costs	(56,890)	(53,379)	(36,508)
Accounts payable, accrued expenses and other liabilities	(14,429)	(28,620)	7,272
Content costs payable	2,967	1,349	4,389
Operating lease liabilities	(6,768)	(6,487)	0
Deferred revenue	4,135	67,725	66,568
Net cash used in operating activities	(2,005)	(60,957)	(7,104)
Cash flows from investing activities:
Purchases of marketable securities	(307,706)	(158,503)	0
Proceeds from maturities of marketable securities	295,800	7,500	0
Purchases of property and equipment	(632)	(1,564)	(5,335)
Capitalized software costs	(12,434)	(14,160)	(12,868)
Purchases of strategic investments	0	(5,000)	(10,000)
Payments related to business combinations	0	(1,500)	(24,490)
Net cash used in investing activities	(24,972)	(173,227)	(52,693)
Cash flows from financing activities:
Net proceeds from exercise of stock options	17,911	7,149	10,878
Taxes paid related to net share settlement of equity awards	(6,760)	0	0
Net proceeds from issuance of redeemable convertible preferred stock	0	0	2
Proceeds from share purchases under employee stock purchase plan	8,044	9,192	0
Payment of redeemable convertible preferred stock issuance costs	0	0	(2,250)
Payment of deferred offering costs	0	(1,586)	(5,183)
Cash proceeds from initial public offering	0	0	415,187
Net cash provided by financing activities	19,195	14,755	418,634
Effect of foreign exchange rates on cash flows	20	(25)	0
Net increase (decrease) in cash, cash equivalents and restricted cash	(7,762)	(219,454)	358,837
Cash, cash equivalents and restricted cash—Beginning of period	317,314	536,768	177,931
Cash, cash equivalents and restricted cash—End of period	309,552	317,314	536,768
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	305,564	313,685	533,868
Restricted cash, current	3,329	0	0
Restricted cash, non-current	659	3,629	2,900
Total cash, cash equivalents and restricted cash	309,552	317,314	536,768
Supplemental disclosures of cash flow information:
Interest paid	3,188	23	90
Income taxes paid	1,418	678	385
Supplemental disclosure of non-cash investing and financing activities:
Stock-based compensation in capitalized costs	9,175	5,911	2,571
Net change in unrealized gain (loss) on marketable securities	289	(213)	0
Unpaid deferred offering costs	0	0	1,586
Acquisition holdback liability	$ 0	$ 0	$ 1,500